- Joined
- Sep 5, 2013
- Messages
- 3,207
I don't know that degreaser would do that although I'm not an expert. A strong caustic chemical is bound to have some effect although I've not been able to successfully reproduce any characteristic failure to date.
I wonder though about repeated stress failure? In the OP picture you can see at the extreme ends of the gear teeth as well as along the sharp corners of the teeth there is what looks like a delamination occurring. I've seen this before, most recently on a previously unused pulley (either NOS or reproduction, not sure) as well as on this example of a change gear.
In the case of the pulley, I was trying to true it up on the lathe and it just continued to fall away at the edges until it ultimately split in half. This gear though is really the dramatic example. The metal has disintigretated to the point it is expanded on the one side giving a substantial crown to the gear. It's quite amazing, really, I keep it around just to look at.
It could be that some of these failures will become more common, I don't know. Age related due to the alloy, perhaps, and we will be seeing it crop up now for the first time since the parts were produced. Don't know, like I said, I'm not an expert. Just curious.
-frank
I wonder though about repeated stress failure? In the OP picture you can see at the extreme ends of the gear teeth as well as along the sharp corners of the teeth there is what looks like a delamination occurring. I've seen this before, most recently on a previously unused pulley (either NOS or reproduction, not sure) as well as on this example of a change gear.
In the case of the pulley, I was trying to true it up on the lathe and it just continued to fall away at the edges until it ultimately split in half. This gear though is really the dramatic example. The metal has disintigretated to the point it is expanded on the one side giving a substantial crown to the gear. It's quite amazing, really, I keep it around just to look at.
It could be that some of these failures will become more common, I don't know. Age related due to the alloy, perhaps, and we will be seeing it crop up now for the first time since the parts were produced. Don't know, like I said, I'm not an expert. Just curious.
-frank
